# Stress Test for Lake

This folder generates a deeply nested import tree of Lean modules
that can then be used as a stress test of large Lake builds (e.g., Mathlib).
The modules lack any code.
This removes variations in Lean elaboration time as a confounding factor,
but also means this test cannot be used to profile features that depend on code size
(e.g., OLean hashing or a module system).

It also generates a test workspace with many requires to benchmark the cost
of importing a multi-package configuration.

## Usage

This folder is tested as part of Lean's speed center benchmarks,
but it can also be run manually like so:

```bash
lake run mkTree
lake -d=test/tree update
time lake -d=test/tree script run nop
lake run mkBuild
time lake build
```

These commands generate the mock packages and source files and then time a configuration import and a build.

## Variations

The source generation configuration is flexible:

```bash
lake run -Ktest=Test mkBuild 40 40
```

The `test` option is which subdirectory of the `Inundation` source directory to output library files.
The first number is the maximum dependency depth, and
the second number is the number of dependencies for each file.

```bash
lake run mkTree 10
```

The number is how many dependency configurations to generate.

The settings in each example are the default values.

## Credits

This test is a fork of Gabriel Ebner's [GitHub repository](https://github.com/gebner/inundation/tree/master). Thank him for the initial idea!